Add search condition to the query. Basically similar to addCondition, but searchconditions make use of the searchmode setting to determine whether the different searchconditions should be and'ed or or'ed.

This override adds special support for comparisons using a subquery instead of a table field. Oracle doesn't allow direct UPPER(...) calls on the subquery result so we need to wrap it inside a select query from dual. To prevent perform loss we try to detect if the comparison field is a subquery or not.